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pub trait Pdep {
fn pdep(self, mask: Self) -> Self;
}
macro_rules! pdep_impl {
($ty:ty) => {
#[inline]
fn pdep_(value: $ty, mut mask: $ty) -> $ty {
let mut res = 0;
let mut bb = 1;
loop {
if mask == 0 {
break;
}
if (value & bb) != 0 {
res |= mask & mask.wrapping_neg();
}
mask &= mask - 1;
bb += bb;
}
res
}
};
($ty:ty, $intr:ident) => {
cfg_if! {
if #[cfg(all(
any(target_arch = "x86", target_arch = "x86_64"),
target_feature = "bmi2"
))] {
#[inline]
#[target_feature(enable = "bmi2")]
unsafe fn pdep_(value: $ty, mask: $ty) -> $ty {
crate::arch::$intr(
value as _,
mask as _,
) as _
}
} else {
pdep_impl!($ty);
}
}
};
}
macro_rules! impl_pdep {
($id:ident $(,$args:ident)*) => {
impl Pdep for $id {
#[inline]
#[allow(unused_unsafe)]
fn pdep(self, mask: Self) -> Self {
pdep_impl!($id $(,$args)*);
unsafe { pdep_(self, mask) }
}
}
}
}
impl_all!(impl_pdep: u8, u16, i8, i16);
cfg_if! {
if #[cfg(any(target_arch = "x86", target_arch = "x86_64"))] {
impl_pdep!(u32, _pdep_u32);
impl_pdep!(i32, _pdep_u32);
cfg_if! {
if #[cfg(target_arch = "x86_64")] {
impl_pdep!(u64, _pdep_u64);
impl_pdep!(i64, _pdep_u64);
} else {
impl_all!(impl_pdep: i64, u64);
}
}
} else {
impl_all!(impl_pdep: u32, i32, i64, u64);
}
}